The present disclosure relates to a zoom tracking controller, a compound-eye imaging apparatus, and a method of control by the zoom tracking controller and, more particularly, to a zoom tracking controller that controls zoom tracking, a compound-eye imaging apparatus, and a method of control by the zoom tracking controller.
There is a demand for recently developed compound-eye imaging apparatuses, which capture images that can create a stereoscopic view, to control zoom tracking. Zoom tracking control is a type of control in which a zoom factor is changed while a focused state is maintained. Specifically, in zoom tracking control, a motor or the like moves a focus lens to a position at which a focus is obtained according to the movement of a zoom lens.
In zoom tracking control by a compound-eye imaging apparatus, a zoom lens and focus lens on the left side and a zoom lens and focus lens on the right side are controlled. For example, a proposed apparatus causes one of the zoom lenses on the right side and left side, which is referred to as the salve, to follow the movement of the other zoom lens, which is referred to as the master (see Japanese Patent Application Publication No. 9-127400, for example). This apparatus uses a differential amplifier and a comparator to detect a difference in position between the two zoom lenses as an error voltage. The apparatus moves the salve zoom lens in a direction in which the detected error voltage is reduced so that a match is obtained in focal length between the optical systems on the right side and left side. Thus, in this apparatus in the related art, the zoom lenses are positioned before the focus lenses on the right side and left side are moved under auto focus control to positions at which a focus is obtained.